Means for compressing fluffy paper pulp to the shape of bales



1954 N. E. STRGMBERG 3, 61,

MEANS FOR COMPRESSING FLUEF'Y PAPER PULP TO THE SHAPE OF BALES FiledDec. 5, 1962 3 Sheets-Sheet 1 SCALE LJ ]T/ME ozmv FIG 1 r f ss %J LW rDec. 15, 1964 N. E. STRC'JMBERG 3,161,124

MEANS FOR COMPRESSING FLUF'FY PAPER PULP TO THE SHAPE OF BALES FiledDec. 3, 1962 5 Sheets-Sheet 2 FIG. 2. 4

L U I' 25 22 75 76 78 77 //9 (P 04: (7/75 l lr// 0 m M a)! Dec. 15, 1964N, E. STRGMBERG MEANS FOR COMPRESSING FLUFFY PAPER PULP TO THE SHAPE OFBALES 3 Sheets-Sheet 3 Filed Dec. 5, 1962 United States Patent In themanufacture of bales of paper pulp it was hitherto usual practice tocompress sheets cut from a continuous web of paper pulp to form bales ofa size suitable for transportation'and pass a wire or iron band aroundeach bale to hold same together.

In order to render the manufacture of the bales, and

more particularly the drying V of the paper pulp, more simple and cheapand reduce the costs of erection as well,

a novel system of operation has been developed and practiced in therecent years.

According to said system the Web or paper pulp is first V freed fromwater in the previously usual way down to a degree of dryness of about45%. By means of special graters the web of paper pulp is then broken upinto wads which are carried away and dried by means of hot air blowersdown to a degree of dryness of about 85%. The product thus obtained isgenerally known as fluffy pulp.

The transformation of the fiuffy pulp into bales of a predeterminedweight and volume, however, is concomitant with great difficulties owingto the extraordinarily large volume the amount of flutfy pulp requiredto constitute a bale occupies in its natural state. In order to form abale which from transportation point of view presents an appropriatehomogeneity, the volume of said amount of fiuffy pulp must be reduced byabout forty times which requires the use of compressing units havingaccordingly large compressing chambers. The'consistency of the fluffypulp renders the collection and the dosage to the compressing unit ofthe correct amount of pulp for each bale more difiicult owing to thefact that pockets having restricted outlets cannot be used without theuse ofmechanical feeding means because of the tendency of the pulptowards hanging and formation of arches.

The weight of the finished bales should, as far as possible, beconstant, since all sale of paper pulp is based upon the nominal baleweight. In existing plants for the manufacture of fiuify paper pulptheproblem of performing the dosage prior to the compressing operationcould not be solved satisfactorily. As a result a manual adjustment ofthe weight of the bales, as by means of an axe or similar implement, hadto be done in certain cases subsequent to the compressing operation. Insuch cases the dosage is usually effected during a given period of timeby means of a time, relay. Thus, in the event of capacity variations ofthe plant prior to the performance of the dosage, the weight of the balewill also vary.

An object of the invention is to permit the collection of apredetermined amount of fluffy pulp and the transformation of saidamount to the shape of a bale with theuse of a press having acompression chamber of essentially reduced dimensions as compared withthe original volume of the amount of fluffy pulp collected for theformation of a bale.

Another object of the invention is to provide means for controlling theamount of pulp to be supplied to the press, which operates independentlyof variations of the capacity of the preceding part of the plant toproduce bales of a constant weight.

A feature of the invention is that the compression of the fluffy pulp tothe shape of a bale, by means of a hydraulic or similar press, ispreceded by one or more precompression stages during the feeding of thepulp to 1 the press.

Another feature of the inventioninvolves that a priice maryprecompression stage is carried out in connection with the transfer ofthe fluffy pulp from a drying plant to a weighing device included in thefeeding mechanism of the press which serves to determine and collect thequantity by weight of flulfy pulp required to form a bale, while asecond precompression stage is carried out in connection with thetransfer of the quantity of fluffy pulp thus determined from saidweighing device to the press.

In an apparatus for carrying the invention into effect, a drying plantfor fluify paper pulp, aweighing device for dosing the quantity offluffy pulp required for each individual bale, and a hydraulic orsimilar press are arranged as a coherent system the various mainelements of which are interconnected by means of screw conveyors.

The features of said main elements will appear from the descriptionhereinafter to follow with reference to the accompanying drawings andwill be more definitely pointed out in the annexed claims.

In the drawings,

FIG. 1 is a partially diagrammatic side elevation of the final stage ofthe drying plant and the upper portion of the weighing device togetherwith the connection therebetween.

FIG. 2 is a part sectional side elevation of the press in its positionready for starting a compressing operation, and the remaining portion ofthe weighing device.

FIG. 3 is a vertical section of the press and associated members in aposition during the feeding out of a completely compressed bale.

FIG. 4 is a part sectional vertical elevation of the press ready forstarting another pressing operation after the delivery of a finishedbale.

With reference to FIG. 1, the numeral 1 designates the lower portion ofa set of cyclones, in which fiuify paper pulp undergoes the final stageof a drying procedure which may be carried out in well-known manner bywellknown means. In said cyclones the dried pulp is separated'fromthehot airused in effecting the drying. The cyclones open each at itsbottom end into a tubular container 2 serving to collect the fluffy pulpdried in the respective cyclone. Said containers 2 open at their bottomends into a horizontal screw conveyor housing 3 containing a pair ofscrew conveyors 3a for feeding the pulp in the direction of the arrow Ato a point above the receiving container 4 of a weighing device Saidweighing device is only indicated in the drawing, represented as it isby a pair of levers 5, since it may be of any appropriate structureknown per se. The weighing device as broadly diagrammatically shown indashed lines in FIG. 1 of the drawing is assumed to act so that upon thesupply to the container 4 of a quantity of fluffy pulp designed to forma bale the weighing device will make a deviation which effects theopening of two flaps 6 serving as the movable bottom of the weighingcontainer 4, thereby allowing the quantity of pulp supplied to thecontainer 4 to drop down in an underlying container hereinafter referredto as collecting container.

In order to adjust the degree of filling of the container 4 towards theend of the filling period means (not shown) may be provided adaptedunder the control of the weighing device to stop the operation of one ofthe screw conveyors 3a in' the housing 3, whereas the speed of the otherscrew conveyor is reduced, as for instance, down to one third of itsnormal value by means of a two-speed motor or by other appropriatemeans, before a full quantity by weight is collected in the weighingcontainer 4. In this way a very exact determination of the weight of thepulp designed to form a bale may be secured.

Due to the action of the cyclones 1 a pressure above atmospheric willunavoidably appear in the containers 2. In certain cases this pressurewill be pulsatory. By arranging so that the housing 3 is permanentlyfilled with pulp, the pulses of said pressure may be prevented frominterfering with the weighing result.

In order under all conditions to be sure that no pressure aboveatmospheric may appear in the weighing container 4 at the supply of pulpthereto, a ventilating pipe 7 leading to the atmosphere is provided atthe delivery end of the housing 3.

Provided below the container 4, FIG. 1, is a pulp collecting container 8as a direct continuation of the weighing container 4, see also FIG. 2.The bottom of the container 8 is steeply inclined to one side, viz. tothe left in the drawing, FIG. 2, and provided thereabove is a screwconveyor 9, acting to transfer the quantity of pulp collected in thecontainer 8 into the press provided by the side of the container 8. Tothis end the screw 9 extends through a conical tubular outlet 10 leadingto the compression chamber of the vertical press cylinder 11.Reciprocating in said compression chamber is a compression head 12 whichperforms its compressing action during its downstroke. Said compressinghead 12 is carried at the bottom end of the rod 13 of a piston (notshown) reeiprocable up and down in a hydraulic cylinder 14.

The press cylinder 11 is open both at its top end, for receiving thecompressing head 12 and the associated piston rod 13, and at its bottomend, for delivering the compressed pulp to a bale mould 15 providedbelow the press cylinder 11 as a continuation thereof. Said bale mould15 comprises a frame slidably mounted on a stationary base 16 whichforms a pressure resisting bottom of the bale mould 15, when the latteris in its normal position right below the press cylinder.

The bale mould 15 may also be displaced laterally from its position onthe base 16, FIG. 2, into a position entirely by the side of the presscylinder, as shown in FIG. 3, and thence back again to its normalposition below the press cylinder, as shown in FIG. 4. Said displacementof the mould is effected by means of a hydraulic or other pressurecylinder 17, the piston rod 18 of which is connected to one side of theframe 15. During its displacement the frame 15 is sliding, in part, onthe base 16 and, in part, on a pair of parallel rails 19 one of whichonly is shown in the drawings, since both of them are located in thesame horizontal plane. During its displacement the frame is guided bymeans of a pair of rails 20 parallel with the rails 19 though located ona higher level.

To remove the finished bale from the frame 15 after the latter with thebale therein has been moved to the side of the press, an upper disc 21and a lower disc 22 are provided vertically above each other and movablevertically to engage the upper and lower surfaces, respectively, of abale in the frame. The surfaces of said discs facing each other areplane and horizontal and of the same size as the upper and lowersurfaces of the bale. The disc 21 has for its object to force the baledownwards out of the bale frame 15, while the disc 22 serves to receivethe bale thus forced downwards and support it while moving downwardsaccording as the upper disc is moving downwards. The movements of thediscs 21 and 22 are controlled by means of hydraulic or similarpower-cylinders 23 and 24, respectively.

By the side of the path as covered by the bale while transferred fromthe frame 15 to the lower disc 22 a plate 25 is pivotally mounted on ahorizontal shaft situated on a level corresponding to that of the lowerdisc 22 when in its uppermost position ready to receive a bale. Thepurpose and operation of said swingable plate will be evident from thedescription of the operation of the press hereinbelow to follow.

The fluffy pulp separated from the hot air following the final dryingstep in the cyclones 1 passes via the containers 2 to the conveyorscrews inside the housing 3 and is fed by said screws to the end of saidhousing situated above the weighing container 4. Under the control of animpulse emitted by the weighing device a preferred reduction of the rateof feed motion is effected towards the end of said motion with a view tosecure the supply to the weighing container 4 of a quantity of fiuffypulp exactly adjusted to form a bale. When the weighing device recordsfull weight, the feed motion is stopped and the bottom flaps 6 areopened under the control of an impulse as emitted by the weighingdevice. As soon as the bottom flaps 6 are opened, the quantity of pulpdetermined by the weighing device is allowed to drop from the container4 down into the collecting container 8.

Simultaneously with the opening of the bottom flaps 6 a time relay (notshown) starts operating, in order after a predetermined period of timecorresponding to the emptying period of the weighing container 4, toemit an impulse for closing the bottom flaps 6. After said closing iscompleted, the conveyor screws inside the housing 3 again start fillingthe weighing container 4.

The weighing container 4 having been filled and the pulp therein havingbeen allowed to drop down into the collecting container 8, the pulpcollected in container 8 will be transferred to the compressing chamberof the press by the action of the screw 9 which by doing this subjectsthe pulp being transferred to a certain degree of precompression. The.entire quantity of pulp collected in the container 8 having been thusprecompressed and transferred to the compressing chamber inside cylinder11 the formation of the bale by subjecting the pulp supplied to thepress cylinder 11 to the action of the compressing head 12 under thecontrol of a time relay started at the same time that the bottom flaps 6of the weighing container 4 are opened. After a bale of the desiredheight or consistency is formed in the frame 15, the compressing actionis interrupted and the compressing head 12 restored to its uppermost ornormal position. When the compressing head during its upstroke haspassed the upper edge of the frame 15 an impulse is given to thehydraulic cylinder 17 to cause its piston rod 18 to move to the left inthe drawing, thereby displacing the frame 15 to the side of the press. Aflat member 26 projecting horizontally from the upper edge of the frame15 on the side thereof which during the movement of the piston rod 18 isfacing rearwards, may act as a bottom of the compressing chamberaccording as the frame 15 is displaced to the side. Thus, as soon as theplate 26 covers the entire bottom end of the cylinder 11 the compressionof the pulp designed to form the next bale may commence by the head 12again moving downwards.

After the frame 15 with the bale therein has reached its lateral endposition, the bale is removedfrom the frame by means of the disc 21which is moved down under the action of the power cylinder 23 to forcethe bale out of the frame.

During the displacement of the frame 1.5 to its position to the side ofthe press, the lower disc 22 is in its uppermost position ready tosupport the bale to be then moved downwards according as the upper disc21 is depressed.

Before the frame 15 with the bale therein is moved to the side of thepress cylinder and while the upper disc 21 is still in its uppermostposition, the swingable plate 25 i swung upwardly about its horizontalaxis through half a revolution in order to place a sheet of wrappingpaper upon the lower disc 22, now in its uppermost position, asindicated in FIG. 2, said sheet having for its purpose to cover thelower surface of the bale. The member 25 is then swung back to its outerposition shown in FIG. 2.

As soon as the upper disc 21 during its downward movement to force thebale out of the frame 15 reaches the lowermost edge of the frame and thebale is, consequently, free from the frame, the downward movement ofdisc 21 is immediately stopped and the disc returned to its uppermost,or normal, position. The frame 15 is now free to be restored to itsposition below the press cylinder 11.

While the" lower" disc 22 with the finished bale resting thereon is inits lowermost position the member 25 is again swung upwardly throughhalf a revolution, this time to place a sheet of wrapping paper on theupper surface of the finished bale, as shown in FIG. 4, to be thenimmediately restored to its outwardly swung position for receivinganother sheet of wrapping paper. The disc 22 with the finished bale maythen be restored to its uppermost position, by the action of the powercylinder 24 and the bale transferred, as by means of a pusher ofwellknown design, from the disc 22 to a conveyor, not shown.

As a result of the restoration of the frame 15 to its position below thepress cylinder 11 the pulp compressed within the cylinder against thetemporary bottom 26 thereof, is allowed to expand down into the space ofthe frame, thereby allowing more pulp to be supplied to the compressingchamber by means of the feeder screw 9.

It is to benoted that the above described structure may be modified inseveral respects without departing from the principle or scope of theinvention. Thus, for instance, more than one feeder screw 9 may beprovided for transferring the fluify pulp from the collecting container8 to the compression chamber. The bale receiving .disc22 may be equippedwith wheels for the transportation of the bale to an unloading place.

I claim:

- 1. A machine for forming bales of a fluffy material by a compressingaction comprising a plant for drying the fluffy material by means of ahot gaseous fluid, a weighing device comprising a container and a scale,,a housing connecting said drying plant with said container, saidhousing having an outlet for the hot gaseous fluid used in the dryingoperation, screw conveying means in said housing for transferring atintervals from the drying plant to the container of the Weighing devicepredetermined quantities of fluffy mass adapted each to form a bale, acontainer for individually collecting each such quantity as deliveredfrom the weighing device, a bale press, means including a screw conveyorat least for transferring each such quantity to said bale press whilesubjecting it to a precompression.

2. A machine for forming bales of a flufly material by a compressingaction comprising a plant for drying the material by means of a hotgaseous fluid, a weighing device comprising a scale and a weighingcontainer, a housing extending between said drying plant and saidcontainer, a screw conveyor in said housing for transferring atintervals predetermined quantities of dried fluffy material from thedrying plant to the container while subjecting it to a precompression,said housing having an outlet for the gaseous fluid used in the dryingoperation,

another container for individually collecting the quantities of fluffymaterial passing through the Weighing container, a bale press having asubstantially vertical compression chamber and an up and down movableplunger therein, a bale mould for communicating wtih said compressionchamber during the bale compression period, and means for withdrawingsaid mould together with a finished bale therein and restoring it tobale forming position after removal of the bale therefrom, and means forremoving the finished bale from the bale mould. n

3. A machine in accordance with claim 2 in which the container of theweighing device is provided with a movable bottom capable of beingopened under the control of the scale to empty the container when thelatter has lowermost portion of the collecting container is connected tothe compression chamber of the bale press by means of a laterallyinclined outlet, a screw conveyor beingprovided in said outlet fortransferring the quantity of fluffy material contained in the collectorcontainer to the compression chamber.

n 6. A machine in accordance with claim 2 in which the compressionchamber of the bale press is of vertical arrangement and open at itsbottom end, the bale mould being of the same inner cross section as thatof the compression chamber and settable to a position directly belowsaid chamber so as to form a bottom portion thereof, said bale mouldbeing slida'ble laterally from its position below the compressionchamber into a position'outside thereof to allow the withdrawal ofafinished bale therefrom.

, 7. A machine in accordance with claim 6 'in which the 'balemouldcomprises a frame open upwardly and downwardly, the bale press beingprovided with a stationary base for supporting said frame during thebale PIfiSS'. ing operation. l V

8. A machine in accordance with claim 7 in which there Q are provided apair of parallel rails extending from one side of said frame supportingbase for supporting the frame during its movements to and from balepressing position.

9. A machine in accordance with claim 8 in which there are another pairof rails parallel with those mentioned in claim 8 for laterally guidingthe frame during= its movements to and from bale pressing position.

1 10. In a machine in accordance with claim 2, and in which the balemould comprises a frame open upwardly and downwardly, the feature thatthe means for removing a finished bale fromthe bale mould frame whenmoved to the side of the bale press comprises an up and down movablemember for removing a finished bale from the frame when locatedvertically therebelow by exerting av downward pressure on the bale, andanother likewise up and down movable member for receiving a bale thusremoved from the frame.

- 11. In a machine in accordance with claim 10 the vprovision of meansfor placing sheets of' wrapping material below and above a baledelivered onto said bale receiving member. a

References Cited in the file of'thispatent UNITED STATES PATENTS 594,008Hanak Nov. 23, 1897 876,553 Hutton et a1. Jan. 14, 1908 2,929,313

Luthman et :al. Mar. 22, 1960 OTHER REFERENCES Paper Trade Journalmagazine (p. 2832), March 18, 1957.

1. A MACHINE FOR FORMING BALES OF A FLUFFY MATERIAL BY A COMPRESSING ACTION COMPRISING A PLANT FOR DRYING THE FLUFFY MATERIAL BY MEANS OF A HOT GASEOUS FLUID, A WEIGHING DEVICE COMPRISING A CONTAINER AND A SCALE, A HOUSING CONNECTING SAID DRYING PLANT WITH SAID CONTAINER, SAID HOUSING HAVING AN OUTLET FOR THE HOT GASEOUS FLUID USED IN THE DRYING OPERATION, SCREW CONVEYING MEANS IN SAID HOUSING FOR TRANSFERRING AT INTERVALS FROM THE DRYING PLANT TO THE CONTAINER OF THE WEIGHING DEVICE PREDETERMINED 